:root {
    --primary-color: #ff6b35;
    --secondary-color: #004e89;
    --accent-color: #1f77b4;
    --bg-light: #f8f9fa;
    --text-dark: #2c3e50;
    --border-color: #e0e0e0;
    --success-color: #2ca02c;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--bg-light);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 3rem 0;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
    font-weight: 700;
}

.tagline {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1rem;
    opacity: 0.9;
}

/* Main Content */
main {
    padding: 3rem 0;
}

section {
    background: white;
    margin-bottom: 2rem;
    padding: 2.5rem;
    border-radius: 12px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

h2 {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-size: 2rem;
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: 0.5rem;
}

h3 {
    color: var(--text-dark);
    margin-top: 1.5rem;
    margin-bottom: 1rem;
    font-size: 1.4rem;
}

/* Intro Section */
.intro ul {
    margin: 1.5rem 0;
    padding-left: 2rem;
}

.intro li {
    margin-bottom: 0.5rem;
}

/* Source Tags */
.sources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 0.75rem;
    margin: 1.5rem 0;
}

.source-tag {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    text-align: center;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    transition: transform 0.2s ease;
}

.source-tag:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.15);
}

/* Showcase Cards */
.showcase-card {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 8px;
    border: 2px solid var(--border-color);
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.showcase-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.showcase-card h3 {
    margin-top: 0;
    color: var(--secondary-color);
}

.showcase-card .button {
    margin-top: 1rem;
}

/* Chart Sections */
.chart-section {
    margin-bottom: 3rem;
}

.chart-description {
    color: #555;
    margin-bottom: 1rem;
    font-size: 1.05rem;
}

.chart-container {
    border: 2px solid var(--border-color);
    border-radius: 8px;
    overflow: hidden;
    background: white;
    margin: 1rem 0;
}

.chart-container iframe {
    width: 100%;
    height: 650px;
    border: none;
    display: block;
}

.chart-note {
    color: #666;
    font-size: 0.95rem;
    font-style: italic;
    margin-top: 0.5rem;
}

/* Data Files */
.file-list {
    list-style: none;
    padding: 0;
}

.file-list li {
    margin-bottom: 0.75rem;
}

.file-list a {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    background: var(--bg-light);
    color: var(--text-dark);
    text-decoration: none;
    border-radius: 6px;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
    font-weight: 500;
}

.file-list a:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: translateX(5px);
}

/* Code Block */
.code-block {
    background: #1e1e1e;
    color: #d4d4d4;
    padding: 1.5rem;
    border-radius: 8px;
    overflow-x: auto;
    margin: 1.5rem 0;
}

.code-block code {
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.95rem;
    line-height: 1.6;
    white-space: pre;
}

/* Usage Section */
.usage ul {
    margin: 1rem 0;
    padding-left: 2rem;
}

.usage li {
    margin-bottom: 0.75rem;
}

.usage code {
    background: var(--bg-light);
    padding: 0.2rem 0.5rem;
    border-radius: 4px;
    font-family: 'Consolas', 'Monaco', 'Courier New', monospace;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.feature {
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: 8px;
    border: 2px solid var(--border-color);
    transition: all 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-color: var(--accent-color);
}

.feature h3 {
    margin-top: 0;
    color: var(--secondary-color);
    font-size: 1.2rem;
}

.feature p {
    color: #666;
    margin: 0;
}

/* CTA Section */
.cta {
    text-align: center;
    background: linear-gradient(135deg, rgba(255, 107, 53, 0.1), rgba(0, 78, 137, 0.1));
}

.button-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.button {
    display: inline-block;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.button.primary {
    background: var(--primary-color);
    color: white;
}

.button.primary:hover {
    background: #e55a2b;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 107, 53, 0.3);
}

.button.secondary {
    background: white;
    color: var(--secondary-color);
    border-color: var(--secondary-color);
}

.button.secondary:hover {
    background: var(--secondary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0, 78, 137, 0.3);
}

.button.disabled {
    background: #ccc;
    color: #666;
    border-color: #ccc;
    cursor: not-allowed;
    opacity: 0.6;
}

.button.disabled:hover {
    background: #ccc;
    color: #666;
    transform: none;
    box-shadow: none;
}

/* Footer */
footer {
    background: var(--text-dark);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

footer p {
    margin-bottom: 0.5rem;
}

.update-info {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Responsive Design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1.2rem;
    }

    section {
        padding: 1.5rem;
    }

    .chart-container iframe {
        height: 500px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .button-group {
        flex-direction: column;
    }

    .button {
        width: 100%;
    }
}